JCF: Metformin deemed safe for both diabetes+heart failure

A clinical trial by University of California, Los Angeles (UCLA) researchers has found that metformin (Glucophage, Bristol-Myers Squibb), a drug used in the treatment of diabetes mellitus, can be a safe method of treatment for patients with both diabetes and systolic heart failure (HF) and may increase survival, according to a study published online Jan. 16 in the Journal of Cardiac Failure.

"There may be over two million individuals with heart failure and type II diabetes mellitus in the U.S. alone,” said senior author Tamara B. Horwich, MD, assistant professor of medicine at the David Geffen School of Medicine at UCLA.

According to previous studies, diabetes increases the risk of developing HF and death among HF patients due to increased amounts of sugar and fat in the bloodstream, accelerating the risk of coronary atherosclerosis. The authors suggested that the best treatment option for diabetes for these patients is still uncertain.

Between 1994 and 2008, Digish D. Shah, MD, and colleagues tested the safety of metformin on 401 patients with an average left ventricular ejection fraction (LVEF) of 24 and an average age of 56. Twenty-five percent were treated with metformin therapy.

Trial participants were split into two groups based on the presence or absence of metformin therapy. In both groups, age, sex, baseline LVEF, medical history and baseline glycosylated hemoglobin were similar, but of those patients treated with metformin, body mass index was higher, creatinine was lower and patients were less likely to be on insulin.

Of the patients treated with the drug, one-year survival rates were 91 percent, while survival rates of patients not treated with metformin were 76 percent, the researchers reported.

"The diabetes drug metformin previously carried a "black box warning" from the FDA against its use in treating diabetes in heart failure patients," Horwich and colleagues wrote. "However, our analysis shows that using metformin to treat diabetes in patients with advanced, systolic heart failure is not only safe, but also may play a role in improving outcomes compared to conventional diabetes care."

Although study outcomes showed progress, prospective studies are needed to determine whether metformin can improve HF outcomes, according to the authors.